The Illearth War (The Chronicles of Thomas Covenant the Unbeliever #2)by Stephen R. Donaldson

After scant days in his "real" world, Thomas Covenant found himself again summoned to the Land. There forty bitter years had passed, while Lord Foul, immortal enemy of the Land, moved to fulfill his prophecy of doom.

The Council of Lords found their spells useless, now that Foul the Despiser held the Illearth Stone, ancient source of evil power, High Lord Elena turned in desperation to Covenant and the legendary white hold magic of his ring. And nobody knew how to use the white hold--least of all, Thomas Covenant.

Thus continues one of the most remarkable epic fantasies ever written...